@h0pE65 Are you in fullscreen or windowed mode? Windowed mode usually uses the f.lux or desktop colors. Borderless windowed mode is also a nice option so you can switch between programs but still have the game displaying over the entire screen.

some games - especially dx9 and "old" engines - won't let any app run over the game : \

many, if not most, dx11/newer games let it work in fullscreen. if it works, prefer fullscreen mode, otherwise use the in-game borderless windowed mode or windowed mode + borderless gaming (or equivalent) to enjoy f.lux and not burn your eyes/brain : F

Speaking of games, another problem: GPU rendered cursors cannot be changed by f.lux. Changing it to a software rendered one means some games in fullscreen that rely on the OS' hardware rendered cursor will end up with no cursor, and it is difficult to navigate the menus having to "guess" where the cursor is based on the buttons highlighting or not. Depending on the UI design, there may not even be highlighting on hover.

I was hoping Microsoft would be able to do something about that in their Night Light implementation in Windows 10's Creators' Update, since they made DirectX, but to no avail.